Does Surgical Excision Reduce Sternotomy Scar Size?

Dear Readers:   With few exceptions, mammalian skin regenerates only its epidermis. The dermis repairs as a scar never quite as perfect in form or function as the original skin. The resulting scar can range in severity from minor to life threatening. Humans have taken only small steps on the path from describing scars to understanding and managing them. Scars are described as normal (gradually fading), hypertrophic (red, raised), or keloid (progressively expanding beyond margins of the original wound). We know scars are more pronounced with increased tension across the scar and time between wounding and complete closure.¹ Wounds kept moist with film or hydrocolloid dressings heal faster and with less scarring than wounds dressed with less moisture-retentive dressings. Normal scars mature for about 1 year, with inflammation subsiding after the first month; although, it may be greater and/or more prolonged in subjects ≤ 30 years old than those ≥ 55 years old—a possible correlate of more vigorous stretching and/or movement. Though science is advancing the description of scar biochemistry and cell biology,¹ we still have much to learn about how to predict or diagnose problem scars, measure them consistently, and prevent or treat them. The 2 articles described in this Evidence Corner help to clarify what works to treat challenging surgical and burn scars. Laura Bolton, PhD, FAPWCA Adjunct Associate Professor Department of Surgery, UMDNJ WOUNDS Editorial Advisory Board Member and Department Editor

Does Surgical Excision Reduce Sternotomy Scar Size?

  Reference: Pai VB, Cummings I. Are there any good treatments for keloid scarring after sternotomy? Interact Cardiovasc Thorac Surg. 2011;13(4):415–418.   Rationale: Sternotomy incisions are prone to form excessive scars. Outcomes of their excision and revision merit review.   Objective: Prepare a “Best Evidence Topic” for efficacy of scar excision with or without adjuvant treatment on reducing scar size after cardiac surgery.   Methods: A MEDLINE literature search from 1950 to November 2010 of “hypertrophic,” “keloid” “scar,” “sternotomy,” and related subjects was used to construct a best evidence topic in cardiovascular and thoracic surgery to answer the question: “In patients with hypertrophic and keloid scarring of the sternotomy wound is surgical excision with or without adjuvant treatment better than no treatment in reducing the size of the scar?”   Results: Of 15 studies found, 9 were tabulated. Of these, 4 were randomized controlled trials (RCTs). No study compared surgical excision with or without adjuvant treatment to “no treatment” controls. Three of these RCTs reported scar improvement over time with no difference between the small samples randomized to receive: 1) surgery + intralesional steroid (n = 16) compared to surgery + oral cochicine (n = 20); 2) 20 subjects treated with 585 nm laser or silicone gel sheet treatment; or 3) 10 patients with scars treated with laser, intralesional steroid, 5-fluorouracil or both. The remaining tabulated RCT reported significant improvement in scar height, erythema, pruritis, and skin surface texture for at least 6 months after scar excision for split halves of hypertrophic and keloid scars (n = 16) treated with the 585 nm pulsed-dye laser compared to no treatment on the other half of each scar.   Two additional studies on silicone gel prevention of scars were reviewed. One 2005 meta-analysis described 13 clinical trials as providing “weak evidence for a benefit of silicone gel sheeting preventing abnormal scarring in high-risk individuals.” This evidence was improved by a later, more rigorous, double-blind RCT. There was less scar height, vascularity, pigmentation, pain, and itchiness and the scar was more pliable 3 months postoperatively in the half of each of 50 median sternotomy incisions dressed with silicone gel compared to placebo (all P values Authors’ Conclusions: Small keloids can be treated radically by surgery and adjuvant therapies. Large and/or multiple keloids are currently only treatable by multimodal interventions to relieve symptoms.

Can Skin Stretching Improve Burn Scar Excision Results?

  Reference: Verhaegen PD, van der Wal MB, Bloemen MC, et al. Sustainable effect of skin stretching for burn scar excision: long-term results of a multicenter randomized controlled trial. Burns. 2011;37(7):1222–1228.   Rationale: Burn survivors often experience large disfiguring scars. Surgical excision and reconstruction of the complete scar area has been performed in 1 step with intraoperative use of a skin-stretching (SS) device with good short-term scar excision outcomes.   Objective: A Phase III, nonblinded RCT compared 3- and 12-month clinical efficacy of large burn scar surgical excisions with or without intraoperative SS device use.   Methods: Subjects in the Red Cross Hospital (Beverwijk, The Netherlands) with burn scars requiring surgical revision and sufficient healthy skin on at least 1 scar edge to accommodate the SS device were randomized to receive scar excision and reconstruction alone (n = 15) or with the SS device (n = 15). Subjects unable to comply with the protocol, or with collagen or elastin disorders, predisposition to form keloids, diabetes mellitus, immunodeficiency or arterial insufficiency, or who were receiving radiation or local or systemic corticosteroids, or whose acute burns exceeded 33% of an extremity’s circumference, were excluded. The primary outcome was scar surface area as percent of the original area 12 months after surgery. Secondary outcomes were 3- and 12-month validated Patient and Observer Scar Assessment Scale scores, scar elasticity (measured using a Cutometer), pigmentation (measured using a Derma Spectrometer), and 12-month scar thickness histologically measured in a biopsy. Results: Scar area reduced more at 12 months in the SS group and was a mean of 26% of the original scar area with the SS or 43% of original area without the SS (P P Authors’ Conclusions: This RCT demonstrates a long-term benefit of SS device use during burn scar excision, improving scar area outcomes without leading to wider or hypertrophic scars.

Clinical Perspective

  It is challenging to distill conclusions to inform scar management choices from available literature. Combined analysis of hypertrophic and keloid scars and variations in subject inclusion characteristics, scar management, and measurement techniques limit comparability of the generally small studies. To the best of current knowledge, scar prevention can be achieved by minimizing tissue trauma (rarely an option for traumatic wounds or burns), by careful, less invasive surgical and closure techniques, and by providing a moist wound and scar environment during healing and scar maturation.^1,4 Interventions with some evidence of efficacy in limiting normal scar development and preventing hypertrophy include silicone gel sheet or other moisture-retentive dressings^1–4 or pulsed dye lasers.^1,6 Modalities meriting further scar prevention RCTs include non-pulsed dye lasers, cryotherapy, radiotherapy, and pressure garments, which reduce burn scar height but fail to improve global scar assessments.   Randomized controlled trials for treating existing excessive scars have generally explored surgical excision techniques, such as Z- or W-plasty and/or intralesionally injected steroids, cytotoxic drugs, or other medications.^1,6 Limited RCT evidence reviewed on small samples may support efficacy of surgical excision of excessive scars,⁶ which appears most successful if the entire scar is excised, then closed by displacing tension to a skin-stretching device.⁷ Adding silicone gel dressings and intralesional injections of 5-fluorouracil may reduce keloid recurrence for at least 1 year compared to excision and silicone gel alone. Many studies were insufficiently powered to reveal significant scar reduction benefits of any intervention over any other,¹ or of surgical excision over other emerging interventions, such as dermabrasions, chemical peels, or follicular unit micrografts. Opportunities to improve scarring outcomes abound as research continues to explore scar prevention or reduction efficacy of various procedures, cytokines, and medications.¹

References

1. Baker R, Urso-Baiarda F, Linge C, Grobbelaar A. Cutaneous scarring: a clinical review. Dermatol Res Pract. Available at: https://www.hindawi.com/journals/drp/2009/625376/cta. Accessed March 2, 2012. 2. Hien NT, Prawer SE, Katz HI. Facilitated wound healing using transparent film dressing following Mohs micrographic surgery. Arch Dermatol. 1988;124:903–906. 3. Michie DD, Hugill JV. Influence of occlusive and impregnated gauze dressings on incisional healing: a prospective, randomized, controlled study. Ann Plast Surg. 1994;32:57–64. 4. Mustoe TA, Gurjala A. The role of the epidermis and the mechanism of action of occlusive dressings in scarring. Wound Repair Regen. 2011;19(Suppl 1):s16–21. 5. Fearmonti R, Bond J, Erdmann D, Levinson H. A review of scar scales and scar measuring devices. Eplasty. 2010;21;10:e43. Available at: https://www.eplasty.com/images/PDF/eplasty10e43.pdf. Accessed March 1, 2012. 6. Pai VB, Cummings I. Are there any good treatments for keloid scarring after sternotomy? Interact Cardiovasc Thorac Surg. 2011;13(4):415–418. 7. Verhaegen PD, van der Wal MB, Bloemen MC, et al. Sustainable effect of skin stretching for burn scar excision: long-term results of a multicenter randomized controlled trial. Burns. 2011;37(7):1222–1228. 8. Chan KY, Lau CL, Adeeb SM, Somasundaram S, Nasir-Zahari M. A randomized, placebo-controlled, double-blind, prospective clinical trial of silicone gel in prevention of hypertrophic scar development in median sternotomy wound. Plast Reconstr Surg. 2005;116:1013–1020. 9. Anzarut A, Olson J, Singh P, Rowe BH, Tredget EE. The effectiveness of pressure garment therapy for the prevention of abnormal scarring after burn injury: a meta-analysis. J Plast Reconstr Aesthet Surg. 2009;62(1):77–84. 10. Hatamipour E, Mehrabi S, Hatamipour M, Ghafarian Shirazi HR. Effects of combined intralesional 5-Fluorouracil and topical silicone in prevention of keloids: a double blind randomized clinical trial study. Acta Med Iran. 2011;49(3):127–130.